The Associated PressPresident Barack Obama waves as he boards Air Force One before his departure from Andrews Air Force Base Monday. Obama previewed his ideas for job creation and economic growth at a Labor Day rally with union members in Detroit.

* Powering down: Despite the proliferation of electronic gadgets, experts expect residential power use to fall over the next decade, reversing an upward trend that has been almost uninterrupted since Thomas Edison invented the modern light bulb.